"Lots of New Zealanders support a change of flag but voted for the current one because the Prime Minister's interference ensured they weren't given a proper choice," she said.

New Zealand First Leader Winston Peters said he gave "credit to the thousands who turned out to prevent change".

"The process was manipulated from the start with a compliant flag panel choosing decisions to the Prime Minister's liking. Mr Key even got the alternative flown on the Auckland Harbour Bridge, paid for by his own department and the Ministry of Transport," he said.

Change-the-flag campaign sees positives

Change The New Zealand Flag chair Lewis Holden said the campaign had won gains for the debate about national identity.

"I'm really actually ecstatic at this result. Not necessarily the result that we wanted, but what it shows you is that there is sentiment for change.

"This has started the debate about our national identity, and that is the really critical thing... New Zealanders actually said, maybe not now, but in the future, we will actually change our flag.

"Those arguments are still valid and I think there's a lot of people who would support change in the future, including many people who didn't vote in this referendum."

The Returned Services Association, which had campaigned to keep the current flag, said it was pleased with the outcome of the referendum.

The association's national vice president, Bob Hill, said it was important that so many people had their say.

"I'm pleased with the result, I must say. But the big thing is that people were given the opportunity to cast their vote and the majority have given their answer.

"The problem that we saw, for people who wanted to retain the flag, is that they might turn around and say 'oh, it's a foregone conclusion, I won't bother voting' so I'm just pleased that people got out there and voted."